Treatment of glass fibres

ABSTRACT

This invention provides a strand chopping apparatus by means of which glass and other strands can be chopped into predetermined lengths without danger to the hands of an operator. The apparatus includes a backing roll and a cutter roll with blades projecting outwards so as to practically touch the backing roll so that strands introduced between the rolls are chopped into the required lengths. The backing roll has a frusto-conical end portion positioned to project through an aperture in a circular guard plate forming part of a guard assembly which also includes a guard box, a slot being provided between the guard plate and the guard box through which strands may be fed sideways into contact with the frusto-conical portion of the backing roll.

United States Patent 1 Thatcher 3,841,184 14 1 .Oct. 15, 1974 TREATMENT OF GLASS FIBRES 75 Inventor: Kenneth Cyril Thatcher, Billinge, h 5- near wigan, England Assistant Examiner-Leon Gilden Attorney, Agent, or FirmWoodard, Weikart, [73] Assignee: Fibreglass Limited, St. Helens, E hardt & Naughton England [22] F1led: Nov. 20, 1972 ABSTRACT [21] Appl. No.: 307,934

This invention provides a strand chopping apparatus by means of which glass and other strands can be Forelgn Application Prlomy Data chopped into predetermined lengths without danger to Nov. 30, 1971 Great Britain 55520/71 the hands of an operator. The apparatus includes a backing roll and a cutter roll with blades projecting [52] US. Cl 83/346, 83/545, 83/860, outwards so as to practically touch the backing roll so 83/913 that strands introduced between therolls are chopped [51] Int. Cl B23d 25/12, B26d 5/08 into the required lengths. The backing roll has a frus- [58] Field of Search 83/343, 346, 544, 545, to-conical end portion positioned to project through 83/860, 51 1, 909, 913 an aperture in a circular guard plate forming part of a guard assembly which also includes a guard box, a slot [56] References Cited being provided between the guard plate and the guard UNITED STATES PATENTS box through which strands may be fed sideways into 2,149 197 2/1939 Topham 83/913 x Contact with the hhsm'cohichl homo of the 3,644,109 2/1972 Klink et al. 65/11 roll- 1 FOREIGN PATENTS OR APPLICATIONS 4 Claims, 3 Drawing Figures 96,446 8/1897 Germany 83/511 IUS.

TREATMENT OF GLASS FIBRES This invention isconcer'ned with the provision of a 'eration' but there is a safety problem in that each strand has to be fed manually into position between the rolls. This leads to the possibility of an accident when the strands are being fed to the high speed chopper which is normally arranged'in line with a bushing from which filaments are drawn and combined into strands.

One object of the present invention is therefore to provide means to avoid-any possible danger to an operator who initially feeds a strand into a chopping appara- In accordance with thepresent invention we provide strand choppingapparatus comprising a backingroll and cutting means associated with the backingroll so that a strand introduced between the backing roll and the cutting means is cut into predetermined lengths characterised by the provision of a frusto-co'nical portion on the backing roll and a slotted guarddevice shaped to prevent the hand of an'operator being caught between'the'roll and the cutting means and to guide a strand through the slot to contact the conical part of the backing roll. I

The guard .deviceipreferablyv includes a box like guard provided w-ith-an opening through which the frusto-conical portion of the backing .roll projects. The

6 through which the strand can be introduced into the apparatus.

In operation the rolls 2, 3, are set to run at say 200 to 300 feet per minute and the strand 1 is hand-pulled vertically downwards in the direction of the arrow A in FIG. 1 so that it extends behind a part of an inturned lip 7 on the guard 4 see FIG. 2. The strand end below the guard 4 is then moved smoothly to the'right in FIG.

1 in the direction of the arrow B and at the same time the drawing motion is continued. In this'movement the strand' 1 is brought from the position C in FIG. I 2

through the aperture 6 to the position D. As soon as the strand 1 makes contact with the frusto-conical end 5 of the backing roll 2 the strand'begins to travel up the conical surface and becomes nipped between a blade on the cutter roll 3 and the'backing roll 2. As soon as this occurs the speed of the rolls 2 and 3 is increased to the required running speed, at which the apparatus is self-clearing, and the lengths chopped on'starting up are thrown clear. Further than that the rapid rotation of the rolls 2, 3, is sufficient to ensure that the strand l continues to be drawn downward so that successive lengths of strand are chopped as the machine continues to operate.

It will be noted that the guard 4 is completely circular and the mounting means (not shown) ispreferably positioned at the top right hand quarter where it does not 'interfere'with the strand or strands. The guard 8 is essentially a box with a hole cutin it toallow the end core of the roll 2 to project and also providing a slot or aperture6 so positioned that a running strand can enter the nip laterally and theslot-is extended horizontally to guard device also preferably includes a substantially circular guardplate arranged around the frusto-conical portion of the backing: roll and provided with an inturned lip.'The cutting means is'preferably in the form of a cutter roll with'projecting blades.-

In operation when cutting strands formed byextrusion from a bushing the axes of the cutter roll and the backing roll-are preferably in substantially the same vertical plane, but when cutting strands from rovings or cake creels the axes of the cutter rolland the backing roll may be in substantially the same horizontal plane.

In order that the invention may be'more clearly understood and readily carried into-effect. reference is now directedto the accompanying drawings given by way of example in which: 3

F 16.1 is a diagrammatic side elevation of apparatus embodying the invention. a I

FIG. 2 is a section on vA--'--A FIG. 3 is a partial view showing how a' cutter roll,-usu-' ally called the chopperbody, co-operates with abacking roll.

' g In FIG. 1 a strandl is seen descending from a bushing indicated generally at 10, abacking roll is shown at 2 and a cutter roll at 3 with blades 9,a circular or similar guard plate 4 being provided around the end of the backing roll which projects through an opening in the wall of a second or box-like guard 8. Referring to FIG. 2 it will be noted that the backing roll 2 has a frustoconical portion 5 at the projecting end and that the guards 4 and- 8 areshaped to provide an aperture or slot allow the strand to be pulled into the'nip. It will be understood that any reasonable numberof strands'can be cut simultaneously, the strands e'ithcr'being fed'in'together as one strand and subsequently separated or being fed in strand by strand one after another when the machine is running sothat the strands distribute themselves along the rolls 2 and 3;

Although in the above description-we have referred to a guard 4'and a second guard 8 the guards may be regarded asforming a single guard assembly to offer a safeguard to'an operator and with a slot or aperture to allow the strands to pass into the apparatus.

Whilst the previous description relates particularly to use of the invention for cutting strands which. have been obtained by vertical drawing from a bushing, the present invention is also of use for cutting strands from rovings or cake-creels. For these latter purposes it is normal to supply roving in a horizontal direction to a cutting apparatus which chops the roving and subsequently delivers the chopped strands in a downward and substantiallyvertical path. In this respect the pres- Y 'ent invention would be operably arranged with the axes v of the cutter roll 3'and backing roll 2 parallel and in a common horizontal plane; Effectively this amounts to rotation of FIG. l'of the accompanyingdrawings through However, though thisarra'ngement is to be preferred, the cutter and backing rolls may be orientated in any manner suitable for carrying out chopping.

Although starting speeds of 200 300 feet/minute are mentioned in the general description of the cutter and its operation, greater starting speeds, say up to 700 feet/minute, may be used if the material being chopped will withstand such starting speeds.

I claim:

LA strand chopping apparatus comprising a backing roll and a cutter roll with projecting blades associated with the backing roll so that strands introduced between the backing roll and the cutter roll are into predetermined lengths characterized in this, that the backing roll is provided with a frusto-conical end portion positioned to project through an aperture in a guard box forming part of a guard assembly which also includes a substantially circular guard plate, a slot being provided between the guard plate and the guard box through which in operation strands are moved sideways into contact with the frusto-conical end portion of the backing roll which guides the strands into a position in which they are nipped between a cutting blade and the is provided with an inturned lip. 

1. A strand chopping apparatus comprising a backing roll and a cutter roll with projecting blades associated with the backing roll so that strands introduced between the backing roll and the cutter roll are into predetermined lengths characterized in this, that the backing roll is provided with a frusto-conical end portion positioned to project through an aperture in a guard box forming part of a guard assembly which also includes a substantially circular guard plate, a slot being provided between the guard plate and the guard box through which in operation strands are moved sideways into contact with the frusto-conical end portion of the backing roll which guides the strands into a position in which they are nipped between a cutting blade and the backing roll and are chopped into predetermined lengths.
 2. An apparatus according to claim 1 characterised in that the axes of the cutter roll and the backing roll are in substantially the same vertical plane.
 3. An apparatus according to claim 1 characterised in that the axes of the cutter roll and the backing roll are in substantially the same horizontal plane.
 4. The apparatus of claim 1 in which the guard plate is provided with an inturned lip. 